The present invention relates generally to a mechanical pencil assembly including an eraser detachably secured to the writing end thereof, said eraser defining a bore therethrough, diameter of said bore larger than the diameter of the writing tip of said mechanical pencil assembly such that said writing tip can be projected therethrough when writing is desired and retracted therefrom when erasure is desired. A further feature of the present invention is a first storage compartment within said pencil wherein additional pencil leads can be stored and a second storage compartment within said pencil wherein additional erasers can be stored.
When writing, drawing, or otherwise using a writing utensil to mark upon a surface, hereafter called writing, erroneous marks can occur. It has become common practice to secure an eraser to the end of a writing utensil opposite the writing end, hereafter called the non-writing end, that can be readily used for erasure. However, to use said eraser, said writing utensil must be turned around to position said eraser at the writing surface, which is a great inconvenience.
Several devices has been proposed to permit erasure via an eraser secured to a writing utensil without requiring said writing utensil to be turned around. One solution is to statically secure an eraser near the writing tip of a writing utensil such that erasure can be accomplished by slightly moving said writing utensil to position said statically secured eraser near the writing surface.
U.S. Pat. No. 6,732,407 (Weiss) discloses a writing implement, which generally comprises a forward-positioned eraser that circumscribes the shaft of the writing implement and that may have an annular or doughnut shape.
U.S. Pat. No. 5,555,602 (Leamond) discloses an eraser device, which generally comprises an elongated cylindrical finger grip section with an internal bore defined therethrough, an internal conical bore section that is aligned with the internal bore so that the device can be slid or fitted onto the writing end of a writing instrument, and at least one eraser arm that extends radially outward from the finger grip section, is angled forward towards the front end of the device, and is configured with an eraser such that an operator can use the eraser by merely tilting and rotating the finger grip section to bring the eraser arm and eraser into contact with a writing surface.
U.S. Pat. No. 4,899,419 (Saleen) discloses a pencil eraser assembly having an elongated hollow eraser sleeve formed to align in elemental parallel spaced relationship with both the frustum shaped segment and the portion of the cylindrical barrel segment of a pencil, in which the sleeve has an opening adjacent to the end point of the frustum segment for holding an elongated eraser plug within the sleeve and adjacent to the pencil lead of the pencil.
Some disadvantages of the preceding devices are that they can be ineffective, obstruct the writing surface, or otherwise obstruct normal writing procedures. Another solution to permit erasure via an eraser secured to a writing utensil without requiring said writing utensil to be turned around is to secure a projectable and retractable eraser on the writing end of said writing utensil such that said eraser can be projected when erasure is desired and retracted when writing is desired.
U.S. Pat. No. 2,815,002 (Mayes) discloses an eraser for mechanical pencils, which generally comprises an eraser that is provided with a centrally disposed longitudinally positioned opening through which the lead extends and which is positioned at the base of the conical-shaped section of the point of the pencil and is slidably mounted and adapted to be actuated by a button on the surface of a barrel of the pencil wherein, should it be desired to make an erasure, the eraser is actuated by the button to slide outwardly beyond the point of the lead with the surrounding conical-shaped portion of the pencil expanding, whereby an erasure may be made and, after completing the erasure, the eraser is adapted to be retracted by the button and the point adapted to be used for writing.
U.S. Pat. No. 2,069,462 (Rouse) discloses a eraser that can be readily projected or extended to cover the writing point of a pencil so that an erasure can be made with the same end of the pencil as is used for writing, which generally comprises a tubular eraser attached to a member that is allowed to slide freely on the tube of a mechanical pencil by means of a force applied by one of the fingers and a spring that provides a restoring force to retract the member when released by the finger used to extend the member.
U.S. Pat. No. 1,580,183 (Veillette) discloses a writing implement with the eraser on the same end as the writing point, which generally comprises an eraser adapted to slidably telescope the writing point by means of a slight movement by one of the fingers during writing and which may then be pulled back by a similar movement of the finger.
U.S. Pat. No. 1,473,090 (Ferry) discloses an attachment for lead pencils that is disposed adjacently to the sharpened end of a pencil where it will not inconvenience the writer, which generally comprises a clasp and an erasing block and may have a sliding movement to dispose the attachment at or below the sharpened end of the pencil for erasing.
A disadvantage of the directly preceding devices is that they can be inconvenient to use since either a constant force must be applied by a writing finger to project and keep projected the eraser, a constant force must be applied by a writing finger retract the eraser which causes that writing finger to come to rest at a position not ideal for writing, or both. Another solution to permit erasure via an eraser secured to a writing utensil without requiring said writing utensil to be turned around is to secure an eraser on the writing end of said writing utensil and permit the writing tip to be projected when writing is desired and retracted when erasure is desired.
U.S. Pat. No. 5,127,130 (Copito) discloses a pencil eraser or erasable ink ball point pen eraser in the shape and form of a cowling sleeve affixed to the front end of either a double-acting mechanical pencil or single-acting ball point pen, wherein the writing elements of the pencil or pen may be withdrawn through spring action, making the eraser available for almost immediate application at the writing end of either instrument to erase whatever writing is to be erased.
Because the directly preceding device makes use of a double-acting mechanical pencil or a single-acting ball point pen, it lacks an effective and convenient means to both project and retract the writing tip and, as it relates to a mechanical pencil, lacks an effective and convenient means to advance a pencil lead forward through the writing tip. Accordingly, what is desired, and not heretofore been developed, is a writing utensil assembly wherein the transition from writing to erasure and from erasure to writing is nearly immediate and nearly effortless. Furthermore, what is desired, and not heretofore been developed, is a writing utensil assembly that includes an eraser secured to the front end thereof and a writing tip that is projectable and retractable wherein the writing fingers rest in the writing position after they are used to project the writing tip towards the writing surface, the writing fingers rest in the erasure position after they are used to retract the writing tip away from the writing surface, and as it relates to mechanical pencils, the desired writing finger permanently rests on or conveniently near a lead-advancing knock member.